Fabricating a ride on deck...

[curryman]

G’day Tractor Forum,

I've recently picked up a Toro Z287L with a seized FH680V engine and a bad deck.

I've cleaned up the engine, honed the cylinders, and soaked the heads in ATF. I reckon it'll run fine with new gaskets and oil.

The deck is a non-original 52-inch replacement, but it’s beyond saving. I've designed a new deck in CAD and plan to have it laser-cut. I also found a set of 3 spindles with pulleys for $120 (Cub Cadet type), and I’ve calculated the blade tip speed at ~18,000 FPM.

I’m considering using chain at the rear instead of solid steel to prevent clogging and allow rocks to pass through. Also, I’ve had an idea to replace blades with chains for durability in rocky terrain.

A few questions:

1. Is this design practical and achievable?


2. What steel thickness (gauge/mm) should I use?


3. Is a chain backing a good idea for rock clearance?


4. Would reinforcing the pulley system with a frame help?


5. Would chains instead of blades work better for heavy grass and rocky terrain?



The goal is a rugged bush mower that handles steep slopes and rocky ground. The mower itself seems solid, with mud tires, so I want a setup that mulches well and resists damage.

What do you reckon?
Thanks for the help.

 

[dadohead]

I'm a retired tractor engineer. I did NOT work on Z's but designed many decks and drives. Several things you mention jump out:

• 18000 fpm
• Chain backing for rock clearance
• Rugged brush mower
• Steep slopes and rocky ground

I recently designed and built a custom rotary cutter. I commend you for tackling such an ambitious project! Lots to digest here.

Let's start with the machine platform: a mid-Z. Usually not ideal for steep slopes (because they are tractively steered). Pros do some amazing things on slopes (and often take some wild rides down if they break traction) but can be sketchy for us mere mortals. The mud tires will help but will be harder on nice turf.

That machine originally had a finish mower. That is NOT ideal for a brush mower that will encounter rocks. You are building a new one and can tweak it.

Start with the blades. You'll need to adopt somebody's production blade because you'll be going through them! Swing blades would be best (they absorb energy from hitting objects). 52" size limits your choices. Maybe a 2 spindle design??? Woods made a 3pt hybrid finish mower with swing blades. Check into those. 18000 is too fast! That is for a pro wanting cut quality at 6 mph.... not for rugged brush mowing! Impact cutting starts at 12000 (below that it just 'combs' the material). 14000 fpm will work well and won't suck all your power. Deep decks process material better; go as deep as you can fit. Regarding steel gauge: REINFORCE THE SPINDLE POCKETS (where the spindles mount). Impact energy will go right to that region. Blades, spindles, belts can be replaced... wonky spindle pockets ruin the deck. I suspect you won't find swing blades so this deck will be absorbing lots of rock hits. JD's heaviest commercial decks are 7ga steel. Europe sells mowers just like you are describing that mount under small tractors.... search for "high grass mowers". They have raised front / rear skirts and chain guards.

Again... lots to digest here. Sorry for the long winded reply. Hope this helps!

 

[dadohead]

Oh yeah.... instead of sourcing my parts to a laser house (which I've done as well), I bought a plasma cutter for my mower project. I made 1/4" plywood templates, clamped to the steel, and followed them just like a router follows a template in wood!

 

[2manyrocks]

How steep is your terrain and could you post a picture of it?

The issue with caster front wheels on steep hills is you have no control over them.

Don't know about your Toro, but many ZTRs don't have any brakes to stop a downhill run.

Many of the gas engines on these types of mowers aren't designed to operate past 20 degree slopes.

 

[curryman]

How steep is your terrain and could you post a picture of it?

The issue with caster front wheels on steep hills is you have no control over them.

Don't know about your Toro, but many ZTRs don't have any brakes to stop a downhill run.

Many of the gas engines on these types of mowers aren't designed to operate past 20 degree slopes.

there are portions of the property that are reasonably flat, and portions of the property that are over 45 degrees. it is 100 acres of mountain, with rocks just about everywhere, there are old terraces and tracks that im planning to use this mower for, but hoping to make it rugged enough to take a beating... it was 500 dollars

 

[dadohead]

I’ve had an idea to replace blades with chains for durability in rocky terrain.

A couple more thoughts come to mind: members here have shared their designs on swapping chain for blades PRIMARILY on single spindle rotary cutters... know that tip clearance is kept fairly tight on multi-spindle mowers to prevent between-blade-striping (.100" typical). Two chains whipping AT each other is beyond wild. Hardened blades can (and do) wear and eventually break. This seems like a liability nightmare. Please be careful.

The other thing that comes to mind is machine balance. As I mentioned, I never worked on mid-Z mowers in my career but I do remember that their balance is carefully designed. They do this to maintain decent traction while traversing hills. Just adding 20lbs toward the front of a Z will change it's dynamic performance greatly on hills. I can't remember the target... 70% rear / 30% front??? Just know that building a larger/heavier mower will negatively effect its handling and ability to negotiate hills. Hope this helps!

 

[2manyrocks]

When I was looking for a slope mower, I didn't find many examples of rough cut slope mowers that use mid-mount decks. There's only so much clearance to the ground. My experience with mid-mount mowers is they tend to push tall and thick material over instead of cutting it. When the slope reaches 30 degrees, that is where you start to only see machines like Ventrac, Power Trac and Steiner rated for this much slope in the USA. I think even Power Trac tops out at 40 degrees. The Swiss have some machines rated for steep slopes, but I didn't seem them readily available for purchase in the USA. These tend to be dual wheel, low slung tractors with front mowers.

In terms of ZTRs in the USA, Cub Cadet sells a line of ZTXS mowers rated for 20 degree slopes that have front steering and ROPS. Zero-Turn Mowers - Zero-Turn Riding Mowers for Sale | Cub Cadet US. Their regular ZTRs with swivel front wheels are rated up to 15 degree slopes.

My concern about this project is that it's going to take a lot of fabrication work to build a deck that will mount to the ZTR, and the end result still won't be safe for operation on steep slopes with a bunch of rocks.

 

[sandman2234]

Does Curryman mention what part of the world he is In?
David from jax

 

[dieselscout80]

I'm a retired tractor engineer. I did NOT work on Z's but designed many decks and drives. Several things you mention jump out:

• 18000 fpm
• Chain backing for rock clearance
• Rugged brush mower
• Steep slopes and rocky ground

I recently designed and built a custom rotary cutter. I commend you for tackling such an ambitious project! Lots to digest here.

Let's start with the machine platform: a mid-Z. Usually not ideal for steep slopes (because they are tractively steered). Pros do some amazing things on slopes (and often take some wild rides down if they break traction) but can be sketchy for us mere mortals. The mud tires will help but will be harder on nice turf.

That machine originally had a finish mower. That is NOT ideal for a brush mower that will encounter rocks. You are building a new one and can tweak it.

Start with the blades. You'll need to adopt somebody's production blade because you'll be going through them! Swing blades would be best (they absorb energy from hitting objects). 52" size limits your choices. Maybe a 2 spindle design??? Woods made a 3pt hybrid finish mower with swing blades. Check into those. 18000 is too fast! That is for a pro wanting cut quality at 6 mph.... not for rugged brush mowing! Impact cutting starts at 12000 (below that it just 'combs' the material). 14000 fpm will work well and won't suck all your power. Deep decks process material better; go as deep as you can fit. Regarding steel gauge: REINFORCE THE SPINDLE POCKETS (where the spindles mount). Impact energy will go right to that region. Blades, spindles, belts can be replaced... wonky spindle pockets ruin the deck. I suspect you won't find swing blades so this deck will be absorbing lots of rock hits. JD's heaviest commercial decks are 7ga steel. Europe sells mowers just like you are describing that mount under small tractors.... search for "high grass mowers". They have raised front / rear skirts and chain guards.

Again... lots to digest here. Sorry for the long winded reply. Hope this helps!

Landpride and Woods make mower with swinging blades that are 90” wide and might make a good source for parts for the build.

Land Pride

www.landpride.com

RD990X - Woods Equipment

Heavy-Duty Your Most Versatile Finish Mower Move from rough, weedy farmland to commercial lawns and landscapes with a finish-cut quality. Easy Maintenance EZ-Change™ Blade System allows blade change in five steps with a 3/4" wrench. No impact gun or torch required. Unmatched Gearbox PROTECTION...

woodsequipment.com

 

[dadohead]

Landpride and Woods make mower with swinging blades that are 90” wide and might make a good source for parts for the build.

I was thinking the same. Even a whole deck would be useful. I see used ones for sale in the $2500 range. Cutting the deck down to a 2-spindle design and using it would really be a great place to start and prolly save money. I've got an inkling it's beyond OP's budget though and the added weight would negatively effect the performance of his mid-Z even more on hills.

I think I'd rather ride a bull than get on a Z @ 45 deg slope.... 8<(